Claudio Ferreira Dias

Geometry-Based Stochastic Channel Model for Two-Story Lobby Environment at 10 GHz

This paper presents a complete parametrization for a three-dimensional (3-D) geometry-based stochastic radio channel model (GSCM) at 10.1 GHz based on a measurement campaign. The radio channel measurements were carried out with a vector network analyzer over a 500 MHz bandwidth in a two-story lobby environment. The measurements were conducted with 9 × 324 dual polarized virtual antenna arrays in line-of-sight (LOS) and non-LOS propagation conditions. The recorded data was post-processed using the estimation of signal parameters via rotation invariance algorithm. The statistical analysis was carried out to provide full 3-D parametrization for the GSCM. The parametrization was verified by radio channel simulations. Multiple-input multiple-output (MIMO) channel is reconstructed from the estimated propagation paths and equivalently the channel simulations are performed by quasi-deterministic radio channel generator using our measurements-based parameters. The channel capacity, Demmel condition number, and relative condition numbers are used as the verification metrics. The results show that the reconstructed MIMO channel matches well the simulated MIMO channel.

Outage Probability for MIMO Relay Channel

The channel capacity for the multiple-input multiple-output (MIMO) relay channel is still an open problem. In view of this gap, upper and lower bounds were found by Wang et al., 2005. This paper presents an extensive study of mutual information and outage probability of Rayleigh fading MIMO relay channels based on the eigenvalues distribution for the sum of complex Wishart matrices. Interestingly, for certain scenarios, upper and lower bounds are coincident providing the real channel capacity. To compute outage probability, a Gaussian approximation for mutual information has been used. Furthermore, it was proposed an equivalent distribution for the sum of Wishart matrices, which proves to be excellent in all scenarios. Closed-form expressions for probability density function and outage probability have been found for the general case of any number of antennas and any SNR values. Analytical expressions have been validated by means of Monte Carlo simulations.

On the Exact and Approximate Eigenvalue Distribution for Sum of Wishart Matrices

The sum of Wishart matrices has an important role in multiple-input multiple-output (MIMO) multiple access channel (MAC) and MIMO relay channel. In this paper, we present a new closed-form expression for the marginal density of one of the unordered eigenvalues of a sum of

Parametrization and Validation of Geometry-Based Stochastic Channel Model for Urban Small Cells at 10 GHz

K

Outage probability of dual-hop decode and forward MIMO relay with co-channel interference

complex central Wishart matrices having covariance matrices proportional to the identity matrix. The expression is general and allows for any set of linear coefficients. The derived expression is used to obtain the ergodic sum-rate capacity for the MIMO-MAC and MIMO relay cases, both as closed-form expressions. We also present a very simple expression to approximate the sum of Wishart matrices by one equivalent Wishart matrix. The agreement between the exact eigenvalue distribution and numerical simulations is perfect, whereas for the approximate solution the difference is indistinguishable.

Diffraction measurements around a building corner at 10 GHz

We derive a full measurement-based parametrization for a 3-D geometry-based stochastic channel model for an urban microcell type of environment at 10 GHz. The measurements were performed with a vector network analyzer and dual polarized virtual arrays at the bandwidth of 500 MHz. The proposed parametrization is validated by channel simulations. Multiple-input multiple-output channel is reconstructed from the measured data and compared with channel generated by the quasi deterministic radio channel generator using the proposed statistical parameters. The capacity and eigenvalue distribution are used as the validation metrics, showing almost perfect match between the reconstructed and simulated channels.

Validation of Deterministic Radio Channel Model by 10 GHz Microcell Measurements

In this paper, the mutual information outage probability (P) for dual-hop decode-and-forward multiple-input multiple-output (MIMO) relay channel is obtained. Rayleigh distribution is used to model MIMO channels, and both full-duplex and half-duplex modes are investigated. Co-channel interference at relay and destination nodes has been considered. Our assumption is based on the result of [1], which establishes that MIMO channel mutual information can be well approximated by a Gaussian distribution. We have found a closed form expression for P given as a function of bivariate Gaussian cumulative density function. The results show for low-medium interference regime that full-duplex performs better than half-duplex mode. On the other hand, when relay self-interference increases, half-duplex outperforms full-duplex mode. Regarding the number of antennas, full-duplex mode performs better than half-duplex mode when number of antennas increases, even in high interference scenario. All the results are validated by numerical Monte Carlo simulations.